Memory is one type of integrated circuitry, and is used in electronic systems for storing data. Integrated memory is usually fabricated in one or more arrays of individual memory cells. The memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.
One type of memory is phase change memory (PCM). Such memory utilizes phase change material as a programmable material. Example phase change materials that may be utilized in PCM are chalcogenide materials.
The phase change materials reversibly transform from one phase to another through application of appropriate electrical stimulus. Each phase may be utilized as a memory state, and thus an individual PCM cell may have two selectable memory states that correspond to two inducible phases of the phase change material.
A problem that may occur during programming of the memory cells of a PCM array is that there may be thermal transfer between adjacent memory cells (so-called “thermal disturb”). Accordingly, the memory state of a memory cell may be disturbed when an adjacent memory cell is programmed, which can lead to unreliability of data storage within a memory array. The problem can increase with increasing downsizing of integration.
It would be desirable to develop PCM cell architectures which alleviate or prevent the above-discussed problem, and to develop methods of forming such PCM cell architectures.